Device for supplying electric power to electronic apparatuses of an acoustic wave receiving assembly of great length

Abstract

A device for supplying electric power to electronic apparatuses of a seismic streamer of great length, comprises an electric feeding assembly associated with each electronic apparatus and including three voltage transformers whose primary windings are respectively fed from a generator with a different phase of a three-phase current, and whose secondary windings are respectively connected to three rectifier bridges supplying the required DC voltage to the electronic apparatus.

We claim: 
     
       1. A device for supplying D.C. current to a plurality of remote acquisition devices located in a seismic streamer wherein data from the remote acquisition devices is transmitted to a central recording assembly located at the beginning end of the streamer, the device comprising: a current generator for generating first, second and third A.C. currents out of phase with one another on three output lines;   three conducting sheaths extending within the seismic streamer, each of the three output lines being connected to one of the conducting sheath;   D.C. power assemblies at locations remote from the beginning of the streamer for providing D.C. current to the acquisition apparatuses, each D.C. power assembly being connected to one acquisition apparatus; each D.C. power assembly comprising three transformers each having a primary winding and a secondary winding with the primary windings being conducted in the three conducting sheaths, the primary windings fed through the same conducting sheath being serially connected; each power assembly further having three rectifier bridges with inputs for A.C. current and positive and negative outputs, the secondary winding of each transformer being connected across the A.C. inputs of one of the rectifying bridges, the positive outputs of the three rectifier bridges being connected to a positive terminal and the negative outputs of the three rectifier bridges being connected to a negative terminal to provide each D.C. power assembly with a D.C. output, the D.C. output of each D.C. power assembly being applied to a seismic acquisition apparatus.   
     
     
       2. A device for supplying D.C. electric power to electric acquisition apparatuses disposed at distance from one another along a seismic streamer said acquisition apparatuses collecting data from seismic transducers and sequentially transmitting data over transmission lines to a central recording assembly, said device comprising a central A.C. current generator generating first, second and third A.C. currents of substantially constant amplitude irrespective of the number of acquisition apparatuses to be fed with electric power, said first, second and third A.C. currents being out of phase with respect to one another, three output lines running along the seismic streamer, a plurality of electric power supply assemblies connected to said three output lines for supplying D.C. currents respectively to each one of said plurality of electronic apparatus of the seismic receiving system, said plurality of electric power supply assemblies comprising A.C. voltage transformer means and voltage rectifying means for converting A.C. voltage to D.C. voltage, said A.C. voltage transformer means in each assembly comprising three voltage transformers whose primary windings are respectively connected to said three feeding lines, the primary windings fed through a same feeding line being serially connected, and said voltage rectifiying means comprising three rectifier bridges with inputs for A.C. current from the secondary windings of the respective transformers and positive and negative outputs between which D.C. voltage is available for feeding the corresponding acquisition apparatus.